Techniques of biochemistry, virology, electron microscopy and computer analysis are used to study picornaviruses and adenoviruses. Analyses of proteins and nucleic acids have been developed and implemented. Graphic representations revealing homology, and reverse complementarity are coupled with numerical methods to aid the prediction of secondary structure, splicing, promotors, and recombination in nucleic acid molecules. Programs are developed and installed in a VAX 11/750 system designed for sequence analysis. Structures of up to 2000 bases have been predicted. Methods to assess the significance of predictions use Monte Carlo simulations, evolutionary comparisons and biochemical data. Protein secondary structure is being predicted from amino acid sequences. New sequences are compared with computerized databases to detect relationships with known proteins. Picornaviruses cause diseases typified by polio, colds, hepatitis, and foot-and-mouth disease. c-DNA clones of rhinovirus having approximately 6000 (of 7000) bases have been isolated and mapped by restriction digests. Sequences are being determined on subclones and are being compared with those of poliovirus and other picornaviruses to determine relationships and to predict properties. Adenoviruses are studied with a goal to understanding early events in replication wherein the cell's metabolism is subverted to viral functions, and late events during which assembly and morphogenesis occurs. Computer analysis of sequences is used to find the structural and functional relationships of intracellular and virion structural nucleic acids and proteins between adenoviruses and their hosts as well as to known proteins from other species.